#include <bits/stdc++.h>
signed main ()
{
	std::ios::sync_with_stdio(false); std::cin.tie(0); std::cout.tie(0);
	int n, m, f = 0; std::cin >> n >> m;
	if (n > m) std::swap(n, m), f = 1;
	std::vector<std::pair<int, int>> ans;
	if (n == 1) for (int i = 1; i <= m; i++) ans.emplace_back(1, i);
	else
	{
		int o = 0;
		for (int i = 1; i <= m; i += n - 1, o ^= 1)
			for (int j = 1 + o; j <= n - o; j++) ans.emplace_back(j, i);
		if ((m - 1) % (n - 1))
		{
			int l = n - o - (m - 1) % (n - 1), r = 1 + o + (m - 1) % n - 1;
			for (int j = l + 1; j <= r - 1; j++) ans.emplace_back(j, m);
		}
	}
	std::cout << ans.size() << '\n';
	for (auto [u, v]: ans) if (f) std::swap(u, v);
	for (auto [u, v]: ans) std::cout << u << " " << v << "\n";
	return 0;
}